The present disclosure relates generally to the field of weather radar systems. More particularly, the present disclosure relates to weather radar systems and methods that enhance airborne weather radar performance based on weather data derived from an external source or combination of external sources.
Weather radar systems are often used to alert operators of vehicles, such as aircraft pilots, of weather hazards in areas near the vehicle, in areas along the vehicle's intended route, at the vehicle's intended final destination, and so on. Such weather radar systems typically include an antenna, a receiver transmitter, a processor, and a display. The weather radar system transmits radar pulses or signals and receives radar return signals indicative of weather conditions. Conventional weather radar systems, such as the WXR 2100 MULTISCAN radar system manufactured by Rockwell Collins, Inc., have Doppler capabilities and can measure or detect parameters such as weather range, weather reflectivity, weather velocity, and weather spectral width or velocity variation. Weather radar systems may also detect outside air temperature, winds at altitude, INS G loads (in-situ turbulence), barometric pressure, humidity, and so on.
Weather radar signals are then processed to provide graphical images to a radar display. The radar display is typically a color display providing graphical images in color that represent the severity of the detected weather. Some aircraft systems also include other hazard warning systems such as a turbulence detection system or a lightning detection system. The turbulence detection system and the lightning detection system can provide indications of the presence of turbulence and lightning, respectively, or other hazards. Conventional weather display systems are configured to display weather data in two dimensions and often operate according to ARINC 453 and 708 standards. Radar displays may display data in various formats and in various views, such as plan views, horizontal views, and vertical views, and may display two-dimensional, three-dimensional, or four-dimensional images.
While aircraft-based weather radar systems may typically provide the most timely and directly relevant weather information to the aircraft crew based on scan time of a few seconds, the performance of aircraft-based weather systems may be limited in several ways. First, typical radar beam widths of aircraft-based weather radar systems are 3 to 10 degrees. Additionally, the range of aircraft-based weather radar systems is typically limited to about 300 nautical miles, and typically most effective within about 80-100 nautical miles. Further, aircraft-based weather radar systems may be subject to ground clutter when the radar beam intersects with terrain, or to path attenuation due to intense precipitation or rainfall.
While the U.S. National Weather Service WSR-88D Next Generation Radar (NEXRAD) radar system and other external data sources have provided significant advancements in the detection and forecasting of weather, externally-received data may include gaps where no data is collected. For example, NEXRAD data may be incomplete or otherwise be missing data due to cone of silence and umbrella of silence regions, insufficient update rates, geographic limitations, or terrain obstructions. Similarly, weather observations and ground infrastructure are conventionally limited over oceans and less-developed land regions. In some instances, weather data received from multiple sources, such as aircraft-based weather radar systems, ground radar systems, satellite systems, and so on, can be combined to provide a better overall representation of current and forecasted weather conditions as well as information that is more complete than weather data derived from one such source. In this way, the range and accuracy of data displayed on aircraft-based weather radar systems may be improved in certain conditions. However, combining weather data from various sources may not provide a complete representation of weather conditions near an aircraft based, for example, on the existence of gaps across all data sources or based on accuracy or other limitations of the external weather data sources.
Aircraft may receive weather data from a variety of external sources, such as ground radar systems, ground lightening detection networks, atmospheric sounding analyses and forecast systems, satellite systems, and other aircraft. For example, aircraft may receive weather information from the NEXRAD radar system, the U.S. Geostationary Operational Environmental Satellite system (GOES), or the Polar Operational Environmental Satellite system (POES). Information provided by aircraft weather radar systems may be used in conjunction with weather information received from external sources to, for example, provide a more complete image of weather conditions on displays, including improved range and accuracy and a reduction of gaps in radar coverage. For example, the NEXRAD weather radar system is conventionally used for the detection of and warning of severe weather conditions in the United States. NEXRAD data is typically more complete than data from aircraft-based weather radar systems due to its use of volume scans of up to 14 different elevation angles with a one degree beam width. Similarly, the National Lightning Detection Network (NLDN) may typically be a reliable source of information for weather conditions exhibiting intense convection. Weather satellite systems, such as the GOES and POES systems, may provide more current data at a much larger range than aircraft-based weather radar systems.
Aircraft may also receive other types of weather data from external sources as well, including Vertically Integrated Liquid Water (VIL) data, Composite Reflectivity (CR) data, data derived from the Storm Cell Identification and Tracking (SCIT) algorithm and/or the Hail Algorithm, Atmospheric Sounding Analyses and Forecasts data, the Freezing Level & −20° C. Level, the Tropopause Level, and a variety of data derived from indices including Convective Available Potential Energy (CAPE), Convective Inhibition (CIN), Equilibrium Level (EL), K Index (KI), Lifted Index (LI), Showalter Stability Index (SSI), Severe Weather Threat SWEAT Index, Total Totals Index (TT), among others.
What is needed is improved systems and methods for enhancing aircraft-based weather radar performance using external data. What is also needed are systems and methods for increasing the accuracy of aircraft-based weather radar systems. What is further needed are systems and methods for configuring aircraft-based weather radar systems based on weather data received from external sources. What is still further needed are systems and methods for classifying weather data acquired by aircraft-based weather radar systems based on weather data received from external sources.